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CMSIS-DAP is the interface firmware for a Debug Unit that connects the Debug Port to USB. Debuggers, which execute on a host computer, connect via USB to the Debug Unit and to the Device that runs the application software. The Debug Unit connects via JTAG or SW to the target Device. ARM Cortex processors provide the CoreSight Debug and Trace Unit. CMSIS-DAP supports target devices that contain one or more Cortex processors.

CMSIS-DAP Overview

The Debug Unit can be an integral part of the evaluation board or an external debug adapter.


CMSIS-DAP can be used with:

  • MDK-ARM V4.54. (or later).
  • The Debug Unit in use must support the Firmware for the CoreSight Debug Access Port (CMSIS-DAP). The firmware gets implemented by the vendor of the device or debug adapter.
  • CMSIS-DAP firmware needs to be version V1.10 or newer to support SWO trace. Verify the firmware in CMSIS-DAP JTAG/SW Adapter.


  • Ask the vendor of the Debug Unit about CMSIS-DAPsupport.
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